1. Field of the Invention
This invention relates to apparatus and a method for effecting prompt, precise control of shape and gauge of strip being rolled in a multistand tandem strip rolling mill.
2. Description of the Prior Art
The need to maintain effective control over the gauge and shape of metal being reduced by rolling mills has been known. Maintaining the desired metal profile becomes more difficult with respect to metal strip and is enhanced as the strip is reduced in thickness.
A further problem is that the existing systems present problems in respect of maintenance as it is generally required to stop the rolling process in order to remove shapemeter sensors and to reinstall the same after repair. It has been known to monitor shape or gauge downstream of a single stand or downstream of the last stand of a multistand mill and to employ this information in adjusting mill settings. See U.S. Pat. Nos. 3,756,050; 3,731,508; and 3,882,709.
It has also been known to employ noncontacting magnetic detectors in attempting to control shape of metal strip in a single stand mill. See U.S. Pat. No. 3,756,050. U.S. Pat. Nos. 3,475,935 and 3,315,506 also disclose systems wherein downstream sensing is employed as a means for attempting to adjust a mill.
U.S. Pat. No. 3,592,031 discloses the use in a tandem mill of upstream and downstream detectors along with computerized processing to control gauge. See also U.S. Pat. No. 3,869,892.
None of the prior patents teach or suggest a system wherein high speed correction of shape and gauge may be effected in a tandem strip rolling mill by feed forward-feedback means.